SVECTORS SVECTORS defines low storage for the RSCS virtual aachine.. It includes two types of
storage: machine-defined and RSCS-defined. • MACHINE-DEFINED LOW STORAGE The SVECTORS aachine-defined low storage defines machine status data referenced during program execution and required by System/370 architecture.
r
, I 0 IPLPSW 40 CSW 1 4 44 1 1 8 IPLCCW 1 48 CIW 1 C I I 4C 1////1////////////////////////////////1 10 IPLCCW2 , 14 50 TIflJER 1 , 18 OLDEXT 54 ////1//////////////1/////////////////1
1C
58 BEWEXT 20 OLDSVC 5C 24 6C BEWSVe 28 OLDPROG 6C 2C 7C IIIEWflJlCH 30 OLDMACH 74
34
78 BEWIO 38 OLDIO 7C 3C Hexadeciaal Field
Displacement Naae Field Description, Contents, flJeaning ------------ -------------------------------------- 0 IPLPSW DS D X'00040000',V(DflJ7INI) 8 IPLCCW1 DS D 10 IPLCCW2 DS D
18 OLD EXT DS D External interrupt old PSW 20 OLDSVC DS D Supervisor call old PSi 28 OLDPROG DS D prograa check old PSW 30 OLDMACH DS D Machine check old PSW 38 OLDIO DS D Input/output old PSW 40 CSW DS D Channel status word
48 CAW DS F Channel address word
4C DS F Reserved for IBM use 50 TIMER DS F 4X' FF' TOn clock
54 DS F Reserved for IBM use
58 NEWEXT DS D X'00040000',V(DM7EXT) 60 NEWSVC DS D X'OO040000',V(DflJ1SVC) 68 NEWPROG DS D X'00040000',A(RIXOUCH) 70 NEWMACH DS D X'00020000',A(OLtfIJACH) 78 NEWIO DS D X'OO040000',V(DflJ7IOMIB) 260 IBM VM/370 Data Areas and Control Block Logic

SVECTOBS • RSCS-DEFIBED LOi STORAGE RSCS-defined low storage begins at hexadecimal .location 200 and is defined specifically
for the RSCS virtual aachine. It contains pointers to aodules that comprise the
supervisor, supervisor control queues, and queues of requests for supervisor services. 200 BEiPSll 204 208 SSAVE 20C 210 ACTIVE 214 !UIBMAP 218 !lIBSIZE 21C QUEUE 220 QUEUEBD 224 FREEQ
228 T1SKQ 22C MPXIOQ 230 SELIOQ 234 IOEXITQ 238 EXTQ 23C ALERTQ 2110 GIVEQ 244 QREQ Hexadecimal Field
I:isplacement Bame ------------ ORG 200 BEiPSi DS 208 SSlVE DS 210 lCTIVE DS DS 214 IUIBM1P DS 218 MIIBSIZE DS SVECTORS+X'200' D D'O' 2F 2F'0' X X'OO' AL3 lL3 (0) V (DMTMIPMS) F F'O' 248 DISP1IJCB 24C iAITRIQ 250 POSTREQ 254 IOREQ 258 TiSKREC 2SC M1IBREQ 2EO ASYBRE(; 264 lLERTBEQ 268 GIVBRlQ 26C TAKEREC 270 TVECTCBO 2711 TVECTCB1 278 TVECTCB2 27C TVECTCB3 280 TVECTCB4 284 TVECTCB5 288 TVECTCB6 28C TVECTCB7 Field Description, Contents, Meaning Leave rooa for machine extensions
Dispatched PSi for last dispatcher
General-purpose low storage save area
Identifier of currently active task
Address of task element for last dispatchee
Address of start of main storage allocation map Total nuater of pages in aain storage
, Section 3. RSCS rata Areas and Contrel Blocks 261